In the fields of medicine, pharmaceuticals, food, etc. where hygienic control is required, a so-called ferrule, which has the shape of a flange with an enlarged diameter and is highly airtight, is often used for a coupling part between pipe conduits or apparatuses which a liquid or a gas to be handled flows through. A liquid passage nozzle of a pipe conduit or an apparatus having this ferrule is coupled with another pipe conduit etc. by means of a ferrule coupling.
In a membrane module used in the medical field, a clamp joint, which can cover the outer periphery of a coupling part between a liquid passage nozzle having a ferrule and a closure member that closes the liquid passage nozzle, and fasten the coupling part with a binding band, is used as a joint for coupling the liquid passage nozzle and the closure member (see Patent Literature 1).